


Pincest Sex Marathon

by orphan_account



Category: Gravity Falls
Genre: F/M, pinecest - Freeform
Language: English
Status: Completed
Published: 2018-12-16
Updated: 2018-12-16
Packaged: 2019-09-20 09:01:53
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 495
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/17019738
Author URL: https://archiveofourown.org/users/orphan_account/pseuds/orphan_account
Summary: Mabel and Dipper are alone at the mystery shack. As horny teenagers do, they fuck.





	Pincest Sex Marathon

**Author's Note:**

> They're both 18 in this btw.

Dipper shouts as thrusts deeper into Mabel to conclude their 11th fuck of the day in their shared room in the mystery shack. Mabel's eyes are glossy as she absently-mindedly wipes away Dipper's seed off her chin. It's a pointless exercise. It's dried in her hair, in her braces, in her ears, all over her forehead. The floor is shiny and slick. Dipper groans and bites Mabel's red raw neck. He can't contain himself. He takes out his throbbing purple dick, slips off the abused condom and grins at Mabel excitedly. 'Wha-what are you doing brosk-?!' She's cut off by Dipper grabbing her face with one hand and crushing the condom in his other over her mouth, making her swallow the white juice.  
'Be a good little slut for me, sister...swallow my cum like a good whore...' his voice is reduced to a raspy groan from screaming in pleasure so many times, his eyes are red from crying because it feels so good to have his own twin sister as his personal whore. 'This is what you get for telling me to use a condom, little girl...do you like that? Being your brother's cumdumpster? Imagine if Gruncle Stan saw you like this...' he trails off into a horny euphoric mess, rambling about how he wants to have Robbie and him spit roast her while Candy watches. His knuckles are white from choking the rubber sheath now, every last drop of kids-to-be flowing into mabel's stomach. Mabel moans in ecstasy as her brother's sperm swims down her throat. She bats her eyelids at Dipper and rolls over on the caked sheets so her stomach is on the bed and her bare ass facing upwards. Dipper gets hard again instantly looking at how perfect her ass is. He spits on his hand, rubs it on his dick and starts humping Mabel like a dog in heat. Mabel screams in pain and pleasure but he doesn't care, shaking hands clutching at porcelain cheeks, leaving red claw marks. He's shaking the whole bed now but he doesn't care. He foams at the mouth because of how good it feels and sounds, his balls colliding with the sensitive area where her vagina and ass become one, making Mabel cry into the pillow at how good it feels. Dipper has went full savage now, squeezing every part of Mabel and grunting as if he was an animal. He speeds up when he's about to come, absolutely destroying Mabel's tight virgin asshole in the process. He's lost all sense now, screaming as his vision blurs and the room spins and his knees give out. He sobs into the damp bedsheets. Mabel snakes her arms around him so her perfectly round and perfect tits are resting on his back. They're both so exhausted and ecstatic they fall asleep on the decimated bed, safe with the knowledge that Gruncle Stan and Soos won't be back at the mystery shack until next week.


End file.
